Charlie Sheen has yet another problem ... he's going to be sued for allegedly derailing an attempt to replace Charlie with his estranged uncle on "Two and a Half Men."
The suit claims Charlie and his dad, Martin Sheen, along with his mom, Janet, conspired to "interfere and restrain" Chuck Lorre from replacing Charlie with Joe Estevez -- Charlie's estranged uncle.
The suit claims the plan was either to have Joe replace Charlie or appear in a spin-off of the sitcom, titled "Uncle Joe."
And the suit claims, Charlie, Martin and Janet also conspired to kill a proposed reality show titled "About the Sheens."
The plaintiff in the case is attorney Ed Meyer, who worked as Joe's manager -- Joe is not a named plaintiff. Meyer tells TMZ he was Joe's business partner in the reality show. Meyer says he's now estranged from Joe.
The suit seeks at least $20 million in damages.